The boy must be sent to the hospital变主动语态

The boy must be sent to the hospital变主动语态
The boy must be sent to the hospital变主动语态

The boy must be sent to the hospital变主动语态
You must send the boy to the hospital.这里,我用了you作主语,你也可以用其他主语（谁送这个男孩去医院）

You/We must send the boy to the hospital.

Someone must send the boy to the hospital.There must be someone to send the boy to the hospital.